Micro channel heat exchanger alloy system

ABSTRACT

A micro channel heat exchanger alloy system is provided and includes first and second manifolds, including a 3000 series aluminum, each of the first and second manifolds being formed to define a respective interior therein, a tube, including at least one of 31108 and 31104 alloy material, extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate, a fin structure, including at least 3003 alloy material, disposed in thermal communication with the tube, the fin structure being cladded with a silicon rich layer, including a 4000 series aluminum and a flux material applied to surfaces of the first and second manifolds, the tube and the fin structure.

CROSS REFERENCE TO RELATED APPLICATION

This application is a National Stage of PCT Application No. PCT/US2012/060419 filed Oct. 16, 2012, which claims the benefit of priority of U.S. Provisional Application No. 61/548,553 filed Oct. 18, 2011, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

Aspects of the present invention relate to micro channel heat exchangers (MCHXs) and, more particularly, to an MCHX alloy system.

Micro channel heat exchangers (MCHXs) and their alloys of construction were developed for automotive applications. Initial applications of these alloy systems resulted in poor corrosion performance, however, in heating, ventilation and air conditioning (HVAC) applications, such as roof top chillers. This problem is especially pronounced in coastal and/or industrial environments, where deterioration of the MCHX tubing can result in refrigerant leaks and system shutdown within a year. In addition, in coastal locations, fin disbonding due to corrosion effects may be a significant problem.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with an aspect of the invention, a micro channel heat exchanger alloy system is provided and includes first and second manifolds, including a 3000 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a tube, including at least one of 31108 and 31104 alloy material, extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; a fin structure, including at least 3003 alloy material, disposed in thermal communication with the tube, the fin structure being cladded with a silicon rich layer, including a 4000 series aluminum; and a flux material applied to surfaces of the first and second manifolds, the tube and the fin structure.

In accordance with another aspect of the invention, a micro channel heat exchanger alloy system is provided and includes first and second manifolds, including a 3000 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a plurality of non-circular tubes, each of the non-circular tubes including at least one of 31108 and 31104 alloy material, and each of the non-circular tubes extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; fin structures, including at least 3003 alloy material, disposed in thermal communication with each of the non-circular tubes, each of the fin structures being cladded with a silicon rich layer, including a 4000 series aluminum; and a flux material applied to surfaces of the first and second manifolds, each of the non-circular tubes, and each of the fin structures.

In accordance with yet another aspect of the invention, a micro channel heat exchanger alloy system is provided and includes first and second manifolds, including a 3003 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a plurality of non-circular tubes, each of the non-circular tubes including at least one of 31108 and 31104 alloy material, and each of the non-circular tubes extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; fin structures, including at least 3003 alloy material, disposed in thermal communication with each of the non-circular tubes, each of the fin structures being cladded with a silicon rich layer, including a 4043 series aluminum; and a lithium modified flux material applied to surfaces of the first and second manifolds, each of the non-circular tubes and each of the fin structures.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side view of a micro channel heat exchanger (MCHX);

FIG. 2 is a perspective view of a tube of the MCHX of FIG. 1;

FIG. 3 is a perspective view of a fin structure of the MCHX of FIG. 1; and

FIG. 4 is a perspective view of a manifold of the MCHX of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

This invention involves aluminum micro channel heat exchanger (MCHX) alloy systems including multi-channel (or multi-port) extruded tubes, with or without sacrificial anodic surface treatments, such as zinc, fin alloys cladded with a silicon rich lower melting point layer, a manifold (or header) alloy and a brazing flux.

With reference to FIGS. 1-4, a micro channel heat exchanger alloy system 10 is provided and includes first and second manifolds 20 and 30, a tube 40, a fin structure 50 and a flux material 60. The first and second manifolds 20 and 30 are volumetric features formed to define respective interiors 21 and 31 therein, as shown in FIG. 4, and are formed of a 3000 series aluminum, which is an aluminum alloy that normally includes about 1.0-1.5 weight per cent (wt %) manganese as well as magnesium. The 3000 series aluminum may be 3003 aluminum, which contains 1.2 wt % manganese and 0.12 wt % copper plus minor elements like iron and silicon as contaminants. The tube 40 includes at least one of 31108 alloy material (especially with lithium flux), which includes 0.21-0.25 wt % silicon, 0.12 wt % iron, 0.01 wt % copper, 0.90-1.10 wt % manganese, 0.05 wt % magnesium, 0.02 wt % chromium, 0.03 wt % zinc and 0.14-0.20 wt % titanium, 31107 alloy material and 31104 alloy material, which includes 0.10 wt % silicon, 0.01 wt % copper, 0.05 wt % magnesium, 0.05 wt % zinc, 0.12 wt % iron, 1.10 wt % manganese (or magnesium), 0.05 wt % chromium and 0.05 wt % titanium, and extends from the first manifold 20 to the second manifold 30. The tube 40 is formed to define multiple channels 41, as shown in FIG. 2, by which the respective interiors 21 and 31 of the first and the second manifolds 20 and 30 fluidly communicate with each other. The fin structure 50 includes at least one of X758, 6815 and 3003 alloy materials and is disposed in thermal communication with the tube 40. The fin structure 50 is further cladded with a silicon rich layer 51, including a 4000 series aluminum, which is an aluminum alloy that normally includes about 4.5-6.0 wt % silicon to form a low melting point alloy for joining or casting purposes, such as 4043 aluminum (5.2 wt % silicon). The flux material 60 is applied to surfaces of the first and second manifolds 20 and 30, the tube 40 and the fin structure 50 and may include lithium modified flux material.

As shown in FIG. 1, the tube 40 may be plural in number with each of the plural tubes 40 extending from the first manifold 20 to the second manifold 30. Each of the plural tubes 40 is also formed to define multiple channels 41. Whether the tube 40 is a single feature or plural features, the tube 40 may have a non-circular cross-section, such as an elongate cross-section, with the multiple channels 41 being arrayed along the non-circular cross-section. For the example of the elongate cross-section, the multiple channels 41 would be arrayed along the elongations of the tube 40.

As shown in FIGS. 1 and 3, the fin structure 50 may also be plural in number with each of the plural fin structures disposed in thermal communication with the tube(s) 40. The fin structures 50 may include louvers 52 arranged along a longitudinal length of the tube(s) 40 to increase fin structure surface area and, therefore, heat transfer.

At least one or more of the first and second manifolds 20 and 30, the tube 40 and the fin structure(s) 50 may each further include a sacrificial anodic surface treatment 70, which may include zinc. In addition, the first and second manifolds 20 and 30 may include titanium.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. 

1. A micro channel heat exchanger alloy system, comprising: first and second manifolds, including a 3000 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a tube, including at least one of 31108 and 31104 alloy material, extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; a fin structure, including at least 3003 alloy material, disposed in thermal communication with the tube, the fin structure being cladded with a silicon rich layer, including a 4000 series aluminum; and a flux material applied to surfaces of the first and second manifolds, the tube and the fin structure.
 2. The system according to claim 1, wherein the tube is plural in number, each of the plural tubes extending from the first to the second manifold and being formed to define multiple channels.
 3. The system according to claim 1, wherein the tube has a non-circular cross-section with the multiple channels being arrayed along the non-circular cross-section.
 4. The system according to claim 1, wherein the fin structure comprises louvers arranged along a longitudinal length of the tube.
 5. The system according to claim 1, wherein at least one or more of the first and second manifolds, the tube and the fin structure comprise a sacrificial anodic surface treatment.
 6. The system according to claim 5, wherein the sacrificial anodic surface treatment comprises zinc.
 7. The system according to claim 1, wherein the first and second manifolds comprise titanium.
 8. The system according to claim 1, wherein the 3000 series aluminum comprises 3003 aluminum.
 9. The system according to claim 1, wherein the 4000 series aluminum comprises 4043 aluminum.
 10. The system according to claim 1, wherein the flux material comprises lithium modified flux.
 11. A micro channel heat exchanger alloy system, comprising: first and second manifolds, including a 3000 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a plurality of non-circular tubes, each of the non-circular tubes including at least one of 31108 and 31104 alloy material, and each of the non-circular tubes extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; fin structures, including at least 3003 alloy material, disposed in thermal communication with each of the non-circular tubes, each of the fin structures being cladded with a silicon rich layer, including a 4000 series aluminum; and a flux material applied to surfaces of the first and second manifolds, each of the non-circular tubes and each of the fin structures.
 12. The system according to claim 11, wherein each of the non-circular tubes has a non-circular cross-section with the multiple channels being arrayed along the non-circular cross-section.
 13. The system according to claim 11, wherein each of the fin structures comprises louvers arranged along a longitudinal length of each of the non-circular tubes.
 14. The system according to claim 11, wherein at least one or more of the first and second manifolds, each of the non-circular tubes and the fin structures comprise a sacrificial anodic surface treatment.
 15. The system according to claim 14, wherein the sacrificial anodic surface treatment comprises zinc.
 16. The system according to claim 11, wherein the first and second manifolds comprise titanium.
 17. The system according to claim 11, wherein the 3000 series aluminum comprises 3003 aluminum.
 18. The system according to claim 11, wherein the 4000 series aluminum comprises 4043 aluminum.
 19. The system according to claim 11, wherein the flux material comprises lithium modified flux.
 20. A micro channel heat exchanger alloy system, comprising: first and second manifolds, including a 3003 series aluminum, each of the first and second manifolds being formed to define a respective interior therein; a plurality of non-circular tubes, each of the non-circular tubes including at least one of 31108 and 31104 alloy material, and each of the non-circular tubes extending from the first to the second manifold and being formed to define multiple channels by which the respective interiors of the first and the second manifolds fluidly communicate; fin structures, including at least 3003 alloy material, disposed in thermal communication with each of the non-circular tubes, each of the fin structures being cladded with a silicon rich layer, including a 4043 series aluminum; and a lithium modified flux material applied to surfaces of the first and second manifolds, each of the non-circular tubes and each of the fin structures. 